K-pop star Choi Seung-hyun (a.k.a. T.O.P.) is convincing as a sensitive kid who becomes a trained assassin in "Commitment," a spy drama with a romantic heart. Boilerplate shootouts and conflagrations get the better of the movie's second half, but for the most part, first-time director Park Hong-soo strikes the right balance between take-no-prisoners espionage and teenage angst.

Set in 2011, screenwriter Kim Soo-young's story spins, somewhat clunkily, around a vaguely defined network of warring sleeper cells from the North operating in Seoul; detectives helpfully point out Kim Jong-il's declining health and the factions' power plays. Myung-hoon (Choi), a 19-year-old from Pyongyang, is thrown into the conflict disguised as a defector to do his handler's murderous bidding. The promised payoff for his stint as a killing machine: He and his sister (Kim Yoo-jeong) will be released from the prison labor camp where they've been paying for their late father's perceived crimes against the North Korean regime.

When he isn't dispatching designated parties, Myung-hoon poses as a high-schooler. His icy aptitude for violence comes in handy against the requisite bullies, while a lovely classmate (Han Ye-ri) brings out his softer side. Orphans and outcasts, their soul-mate friendship plays out with a nicely understated tenderness.

Although one character maintains a fierce devotion to the idea of revolution, there's no philosophical grounding to the spy-versus-spy exploits. That's a key point of the film: Lucre and gangland crime take precedence over ideology, and an innocent generation bears the burden of old hostilities.